A transfer foil having an optical diffraction structure forming layer is utilized for the purposes of improving design performance and security performance. The optical diffraction structure having a fine concavo-convex relief structure such as a hologram and a diffraction grating is formed in the optical diffraction structure forming layer. There is a known method of coloring the optical diffraction structure in order to improve the design performance and the security performance. For example, there is a known colored layer transfer material having a fine relief structure and a reflecting layer made of a metal colored a unique color (For example, see Patent Documents 1 and 2), as a colored layer transfer material to obtain an effect of looking like a colored optical diffraction structure (hereinafter sometimes referred to as “colored hologram”). The inventor also discloses a layer configuration, in which the optical diffraction structure forming layer and the reflecting layer are laminated and a colored layer is added to an observation side to the reflecting layer in order to obtain the effect of looking like the colored hologram (For example, see Patent Documents 3 and 4).
There is a known colored layer transfer material having the colored layer and the metal layer (the reflecting layer) and sensuously looking like, for example, gold (For example, see Patent Documents 5 to 7), as the colored layer transfer material which can be transferred onto a transfer body to obtain a colored-metal glossy color. However, in the above colored layer transfer materials, because the fine concavo-convex relief structure such as a hologram and a diffraction grating which exerts the optical diffraction effect is not provided, the particular design or the optical effect cannot be obtained.
On the other hand, there is also a known method of forming an optical diffraction structure portion having optical diffraction structure in a halftone dot state to add a decorative effect by diffracted light to an image, by transferring the optical diffraction structure in a halftone dot state onto a base material having a predetermined image (For example, see Patent Documents 8 to 10).
Patent Document 1: Japanese Patent Laid-Open No. 09-160475
Patent Document 2: Japanese Patent Laid-Open No. 08-328456
Patent Document 3: Japanese Patent Laid-Open No. 61-238079
Patent Document 4: Japanese Patent Laid-Open No. 62-17784
Patent Document 5: Japanese Patent Laid-Open No. 63-30288
Patent Document 6: Japanese Patent Laid-Open No. 63-230389
Patent Document 7: Japanese Patent Laid-Open No. 09-11638
Patent Document 8: Japanese Patent Laid-Open No. 08-123299
Patent Document 9: Japanese Patent Laid-Open No. 11-227368
Patent Document 10: Japanese Patent Laid-Open No. 2004-101834